Patricia Pastor

Methicillin-Resistant Staphylococcus aureus in Two Child Care Centers

Methicillin-resistant Staphylococcus aureus (MRSA) has not been studied in child care centers. The prevalence of MRSA colonization was determined at two centers with an index patient. Two (3%) of 61 children at center X had MRSA; strains from both children and the index illness were pulsed-field gel electrophoresis type B. Nine (24%) of 40 children at center Y had MRSA; strains from 5 children and the index illness were type B, and strains from 4 children were type A. Ten of 11 colonized children were in classes with 2- and 3-year-old children. Colonization with MRSA was not associated with health care contact by subjects or by members of their households. MRSA in child day care centers indicates accelerated spread of MRSA in the community.

Decreased Haemophilus colonization in children vaccinated with Haemophilus influenzae type b conjugate vaccine

OBJECTIVEnThe incidence of invasive Haemophilus disease has unexpectedly decreased in unvaccinated children since the introduction of conjugate vaccine in the United States. The purpose of this study was to determine whether conjugate vaccination decreases colonization with Haemophilus influenzae type b.nnnDESIGNnThis study was a prospective, bimonthly survey of pharyngeal colonization with H. influenzae type b in children attending day care from October 1987 through September 1989. Vaccination status was determined from the medical record.nnnSUBJECTSnWe obtained 1188 pharyngeal cultures from 283 healthy children, 18 to 59 months of age; 51 children had received unconjugated polysaccharide vaccine (PRP), and 89 had received conjugate vaccine (94% PRP-diphtheria toxoid).nnnMEASUREMENTS AND RESULTSnMultivariate analysis was used to test the possibility of an association between vaccination status and the rate of colonization with H. influenzae type b. Among children known to be exposed to at least one child with a positive culture result, the efficacy of conjugate vaccination to prevent H. influenzae type b colonization in an unmatched analysis was 64% (95% confidence interval: 5%, 86%; p = 0.02) and in a matched analysis 81% (95% confidence interval: 7%, 96%; p = 0.02). No effect on colonization was found with PRP vaccination.nnnCONCLUSIONSnConjugate vaccination decreases H. influenzae type b pharyngeal colonization and thereby may decrease transmission of this agent among healthy children.

Invasive Pneumococcal Disease in Dallas County, Texas: Results from Population-Based Surveillance in 1995

We studied the epidemiology of invasive disease caused by Streptococcus pneumoniae in 1995 among 1.9 million residents of Dallas County, Texas. The sociodemographic characteristics and chronic medical conditions of 432 patients were identified through active, population-based surveillance and review of medical records. The incidence of disease was 22 cases per 100,000 person-years and was highest for children < 2 years of age (136 cases per 100,000 person-years) and for adults > or = 65 years of age (80 cases per 100,000 person-years). Twenty percent of isolates were nonsusceptible to penicillin; the highest rates of resistance were among the youngest and oldest age groups (28% and 22% of isolates, respectively). An increased incidence of disease was associated with low income (42 cases per 100,000 person-years) and black race (39 cases per 100,000 person-years). The frequency of most chronic medical conditions increased with age; smoking, heavy alcohol use, and infection due to human immunodeficiency virus were most common between 30 and 64 years of age. Of otherwise healthy patients 30-64 years of age, 47% were current smokers, an association requiring further investigation. Characterizing groups at risk for invasive pneumococcal disease could aid in the development of prevention programs and increase the benefits from wide use of effective vaccines.

Trends in congenital heart disease in Dallas County births. 1971-1984.

To examine the changes in birth cohort prevalence rates and severity of congenital heart disease, we studied children with congenital heart disease born to blacks, whites, and Mexican-Americans in Dallas County from 1971 through 1984. Diagnoses were made by pediatric cardiologists clinical evaluations, echocardiography, catheterization, surgery, or autopsy. During this study period, 2,509 of 379,561 liveborn infants were diagnosed, a prevalence rate of 6.6/1000. The rates for whites was significantly higher than for blacks or Mexican-Americans--7.2/1,000, 5.6/1,000, and 5.9/1,000, respectively. The rate for severe cases requiring cardiac catheterization or surgery or undergoing autopsy was 3.1/1,000 and did not differ among the three groups. The time trend for rates of congenital heart disease suggested an apparent increase in prevalence rate during the 1970s; however, the prevalence rate of severe forms remained relatively stable. This indicates that the apparent rise in prevalence could be accounted for by an increase in detection of mild cases. These findings were interpreted as reflecting a greater tendency for pediatricians to refer asymptomatic children with significant heart murmurs to a pediatric cardiologist.

Complementary Prognostic Value of Cystatin C, N-Terminal Pro-B-Type Natriuretic Peptide and Cardiac Troponin T in Patients With Acute Heart Failure

The aims of this study were to compare the prognostic value of cystatin C over creatinine and the Modification of Diet in Renal Disease (MDRD) equation and to evaluate whether it provides complementary information to cardiac biomarkers in the risk stratification of an unselected cohort of patients with acute heart failure. Consecutive hospitalized patients with established diagnoses of acute heart failure were prospectively studied. Blood samples were collected on hospital arrival to determine cystatin C, cardiac troponin T, and N-terminal-pro-brain natriuretic peptide. Clinical follow-up was obtained, and the occurrence of mortality and/or heart failure readmission was registered. One hundred thirty-eight patients (median age 74 years, interquartile range 67 to 80; 54% men) were studied. During a median follow-up period of 261 days (interquartile range 161 to 449), 60 patients (43.5%) presented with adverse events. After multivariate adjustment, cystatin C, N-terminal-pro-brain natriuretic peptide, cardiac troponin T, New York Heart Association functional class III or IV, and diabetes mellitus were identified as independent predictors of mortality and/or heart failure readmission. In contrast to creatinine and the MDRD equation, the highest cystatin C tertile (>1.50 mg/L) was a significant independent risk factor for adverse events (hazard ratio 3.08, 95% confidence interval 1.54 to 6.14, p = 0.004). A multimarker approach combining cardiac troponin T, N-terminal-pro-brain natriuretic peptide, and cystatin C improved risk stratification further, showing that patients with 2 (hazard ratio 2.37, 95% confidence interval 1.10 to 5.71) or 3 (hazard ratio 3.64, 95% confidence interval 1.55 to 8.56) elevated biomarkers had a higher risk for adverse events than patients with no elevated biomarkers (p for trend = 0.015). In conclusion, in this unselected cohort, cystatin C was a stronger predictor of adverse events than conventional measures of kidney function. In addition, cystatin C offered complementary prognostic information to cardiac biomarkers and could help clinicians perform more accurate risk stratification of patients with acute heart failure.

β-trace protein and cystatin C as predictors of long-term outcomes in patients with acute heart failure.

OBJECTIVESnThe purpose of this study was to evaluate the prognostic importance of novel markers of renal dysfunction among patients with acutely destabilized heart failure (ADHF).nnnBACKGROUNDnβ-trace protein (BTP) and cystatin C are newer biomarkers for renal dysfunction; the prognostic importance of these tests, particularly BTP, relative to standard measures of renal function remains unclear.nnnMETHODSnA total of 220 consecutive hospitalized patients with ADHF were prospectively studied. Blood samples were collected on presentation. In-hospital worsening renal function, as well as mortality and/or heart failure (HF) hospitalization, over a median follow-up period of 500 days was examined as a function of BTP or cystatin C concentrations; results were compared with creatinine, estimated glomerular filtration rate, and blood urea nitrogen.nnnRESULTSnNeither BTP nor cystatin C was associated with worsening renal function during the index hospitalization. A total of 116 patients (53%) either died or were hospitalized for HF during follow-up. Those with adverse outcomes had higher BTP (1.04 mg/l [range 0.80 to 1.49 mg/l] vs. 0.88 mg/l [range 0.68 to 1.17 mg/l], p = 0.003) and cystatin C (1.29 mg/l [range 1.00 to 1.71 mg/l] vs. 1.03 mg/l [range 0.86 to 1.43 mg/l], p = 0.001). After multivariable adjustment, both BTP (hazard ratio: 1.41, 95% confidence interval: 1.06 to 1.88; p = 0.018) and cystatin C (hazard ratio: 1.50, 95% confidence interval: 1.13 to 2.01; p = 0.006) were significant predictors of death/HF hospitalization, whereas serum creatinine, estimated glomerular filtration rate, and blood urea nitrogen were no longer significant. In patients with an estimated glomerular filtration rate >60 ml/min/1.73 m(2), elevated concentrations of BTP and cystatin C were still associated with significantly higher risk of adverse clinical events (p < 0.05). Net reclassification index analysis suggested cystatin C and BTP deliver comparable information regarding prognosis.nnnCONCLUSIONSnAmong patients hospitalized with ADHF, BTP and cystatin C predict risk of death and/or HF hospitalization and are superior to standard measures of renal function for this indication.

Differential enhancement of postischemic segmental systolic thickening by diltiazem

Prolonged depression of segmental systolic thickening after brief coronary artery occlusion may result principally from events during reperfusion rather than during the ischemic interval. Thus, cellular calcium overload at reperfusion may be a mediator of contractile dysfunction after brief ischemia, and reduction of calcium entry by diltiazem, a calcium channel antagonist, may enhance recovery of systolic thickening after brief periods of ischemia. Thirteen awake unsedated dogs instrumented with hemodynamic catheters, left anterior descending coronary artery occluders and five to six pairs of intramyocardial sonomicrometers underwent two 15 min coronary artery occlusions with 24 h reperfusion. The order of infusion of diltiazem (15 micrograms/kg per min) or saline solution was alternated. Systolic thickening, hemodynamic variables and regional myocardial blood flow were measured serially over 24 h. Despite equally severe ischemic dysfunction during coronary occlusion, diltiazem-treated segments with systolic thinning during ischemia recovered control segmental thickening significantly earlier than saline solution-treated segments (at 30 versus 180 min of reperfusion). Blood pressure was mildly decreased during diltiazem treatment; therefore, a second group of 10 dogs underwent a similar occlusion and reflow period during infusion of nitroprusside to lower mean arterial pressure equivalently. Decreases in blood pressure in this group resulted in some improvement in segmental systolic function; however, this did not reach statistical significance at any time. Regional myocardial blood flows were similar in the saline solution- and diltiazem-treated groups during ischemia and reflow. Thus, it is concluded that 1) diltiazem infusion significantly enhanced recovery of segmental systolic thickening after 15 min of ischemia and 24 h of reperfusion; 2) the enhancement in segmental systolic function could not entirely be attributed to decreased mean arterial pressure; 3) improvement in postischemic segmental ventricular function was seen only in those segments with systolic thinning during ischemia; thus, segments with the most severe ischemic dysfunction benefited most; and 4) there were no important differences in regional myocardial blood flow during ischemia and reperfusion between saline- and diltiazem-treated animals.

Meningococcal disease in Dallas County, Texas : Results of a six-year population-based study

Objective. Neisseria meningitidis is an important cause of serious bacterial infection in children and adults in the US. From 1992 to 1997 invasive disease caused by N. meningitidis was studied among 1.9 million residents of Dallas County, TX. Methods. The demographic characteristics and diagnoses of 151 patients were identified through active, population‐based surveillance and review of medical records. Serogroups were determined for strains infecting 129 (85%) patients. Results. The average annualized incidence rate was 1.3 cases per 100 000 person years and was highest for children <1 year (13 cases/100 000 person years). Older patients (50+ years old) were more likely to present with pneumonia and less likely to present with meningitis than younger patients. Neither the fatality rate nor the duration of hospitalization for surviving patients was associated with age. Among patients with a known serogroup, serogroup C disease was found in 35% of cases <1 year old, 64% of those 1 to 49 years old and 44% of those 50+ years old. Serogroup B strains were isolated from 26% of patients <1 year, 17% of patients 1 to 49 years old and none of the patients 50+ years old. Serogroup Y disease increased from 22% to 35% of cases between 1992 and 1997 (P = 0.03). This serogroup was identified in 26% of patients <1 year old, 17% of patients 1 to 49 years old and in 50% of patients 50+ years old. Serogroup C and Y accounted for 61% of cases in children <1 year old and for 79% of cases in all age groups. Conclusion. The results underscore the importance of conjugate vaccines for serogroups C and Y.

Impact of Kidney Dysfunction on Plasma and Urinary N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Acute Heart Failure

The precise mechanism explaining the increased N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations among patients with concomitant acute heart failure (AHF) and kidney dysfunction is not fully understood. The aim of this study was to assess the impact of kidney dysfunction on simultaneous measures of plasma and urinary NT-proBNP in an unselected cohort of patients with AHF. One hundred thirty-eight consecutive hospitalized patients (median age: 74 years; interquartile range: 67-80 years; 54% male) with a diagnosis of AHF were prospectively studied. Blood and urine samples were collected on hospital arrival to determine NT-proBNP concentrations. Both plasma and urinary NT-proBNP concentrations increased with declining estimated glomerular filtration rate (eGFR; P<.001 for both). However, after multivariate adjustment, eGFR was found to be an independent predictor of plasma (but not urinary) NT-proBNP concentration (eGFR: β=-0.19; P=.016). Indeed, plasma NT-proBNP was the main independent determinant of its urinary concentration (β=0.42; P<.001), and the ratio of urine/plasma NT-proBNP was independent of kidney function and similar across the range of eGFR examined (P=.368). In patients with AHF and concomitant kidney dysfunction, the increased circulating NT-proBNP may be mainly related to increased cardiac secretion and not decreased renal clearance.

Factors associated with unnecessary immunization given to children.

OBJECTIVEnTo determine the factors associated with unnecessary immunization during the pre-school years.nnnMETHODSnChildren were selected from birth certificates and their parents were interviewed to identify all immunizations to 72 months of age. The immunizations were verified.nnnRESULTSnOf 187 children studied 34 (18%) received unnecessary immunization. Unnecessary immunization was strongly associated with ever receiving immunization in a large system of public clinics (designated Public A) (33%) compared with other providers (5%) (P < 0.00001). Among children immunized in Public A, unnecessary immunization was associated with the parent having an incomplete or no copy of the childs immunization record (P = 0.007) and with not being up to date for immunizations at 24 months of age (P = 0.04). Complete documentation of immunizations either in the Public. A record or in the parents copy of the record was associated with a 4% rate of unnecessary immunization; incomplete or no documentation in both the Public A and the parents record was associated with a 45% rate of unnecessary immunization (P = 0.001).nnnCONCLUSIONSnAccess to a complete immunization record, be it the providers, the parents or ideally both, decreases substantially a childs risk of unnecessary immunization.